There are different degrees of damage to the knee joint from playing shuttlecock. There will be obvious damage and mild damage, as follows: 1. Obvious damage: For patients with weak muscles, especially in the lower limbs, playing shuttlecock will increase the wear and tear of the knee joint, especially the articular cartilage. In the process of joint flexion, the meniscus can also be damaged, so there will be significant damage to the knee joint, which in the long run can cause severe pain, limited movement and accelerated degeneration of the knee joint. 2. Mild damage: For patients with strong lower limb muscles, playing shuttlecock can only cause mild damage to the knee joint. Because the muscles protect the joint and prevent it from moving excessively during exercise, thus protecting the articular cartilage and meniscus, even if there is some wear and tear it is only a mild injury and does not cause significant clinical symptoms. Therefore, kicking the shuttlecock can cause different degrees of damage to the knee joint in different patients.